A conventional image forming device, for example, a printer, a photocopier, a facsimile machine, a multifunction machine, or the like, has an image forming unit. This image forming unit has a photoreceptor drum, a charge roller, a developing part, and so on. An LED head exposes the surface of the photoreceptor drum, which is uniformly charged by the charge roller, to form an electrostatic latent image. Then, the electrostatic latent image is developed by the developing part to form a toner image. The toner image is then transferred onto a sheet of paper by a transferring roller. The transferred toner image on the sheet of paper is fused by a fuser to form an image, and therefore, a printing operation is performed.
The developing part is located such that it contacts and pressed the photoreceptor drum. The developing part has a developing roller that operates to adhere toner onto the photoreceptor drum, a toner supplying roller that is located such that it contacts and presses the developing roller and supplies toner to the developing roller and so on.
When the photoreceptor drum is a first rotating body and the developing roller is a second rotating body, the first and second rotating bodies are required to uniformly contact and press each other in the shaft directions of the bodies during the course of assembling the printer. When the first and second rotating bodies are assembled in the printer, the position of the second rotating body is changed and adjusted while the pressing force is measured. Therefore, after the pressing force is adjusted, the first and second rotating bodies are assembled in the main body of the printer, i.e., the device main body. Japanese laid-open patent application publication number 2006-48018 provides an example of such a device.
Similarly, when the developing roller is a first rotating body and the toner supplying roller is a second rotating body, the first and second rotating bodies are required to uniformly contact and press each other in the shaft directions of the bodies. Side plates in which the size is controlled are provided on the both ends of the first and second rotating bodies, and then the first and second rotating bodies are assembled in the device main body. Japanese laid-open patent application publication number 2007-17472 provides an example of such a device.
However, in the conventional printer, it takes time for adjustment work when the first and second rotating bodies are uniformly contacted and pressed against each other in the shaft directions of the bodies. As a result, productivity (?) for assembling the printer was decreased.
Objects of the present invention are to provide an image forming unit and an image forming device in which first and second rotating bodies are easily and uniformly contacted and pressed against each other in the shaft directions of the bodies.